DE1645812C - Process for obtaining a lubricating oil - Google Patents

Description

Solvent refined paraffin oils are typically quite high in paraffin and, as a result, exhibit a low viscosity fairly high values for pour point and cloud point. To lubricate with low To gain pour point, you have to remove these paraffinic materials, which z. B. in known Way z. B. can be done with the help of methyl ethyl ketone-toluene as a solvent.

The figure shows the working sequence in the case of the invention Extraction of lubricating oils. Crude oil is fed into the crude oil distillation plant 2 via line 1, in which it is divided into lower-boiling fractions, such as gas, fuel deatiUate and gas oils, which are about Line 3 are applied, in lubricating oil distillates, which are passed on via line 5, and in the Crude oil residue is broken down, which is discharged via line 4. The lubricating oil distillate enters the Solvent extraction plant 6, where it by treating with NMP in the Schmie.ölextrakt, the is discharged via line 7, and is broken down into raffinate oil; the latter is fed via line 8 into the wax refinement plant 9 transferred. There the waxes are removed and applied via line 10. The raffinate oil which has not been paraffinized in this way is passed through a line 11 withdrawn, mixed with inhibitor supplied via line 12 and finally via line 13 transferred to the mixing plant for the lubricating oil commercial product.

example 1

In one embodiment of the method according to the invention, a crude oil vacuum distillate referred to as wax distillate 20 with the characteristics: SUS viscosity 430 at 37.8 and 56.0 at 99 ° C, viscosity index 73.5, refractive index 1.4820 at 70 ^{r served as the lubricating oil starting material} C and Lovibond Tintometer color number 580 (with 1.27 cm cuvette). The starting material was brought into contact with NMP on the one hand and with furfural on the other hand for comparison purposes in a batch-wise single-stage extractor. The test conditions and results are summarized in the following table I:

Table I.

^ search conditions
solvent

Solvent dosage in%

Working temperature in ⁰ C

Raffinate yield in percent by volume

Raffinate parameters:

SUS viscosity at 37.8 ° C.

SUS viscosity; at 99.0 ⁰ C ..
Viscosity index

Color number (measured with a

1.27 cm cuvette ¹

Refractive index at 70 ⁰ C ..

Furfural

200
66

85

3i7
52.6
91.0

50 Ί
1.4705

NMP

200
66

75

265
51.9
110.5

20th
1.4680

Example 2

Example 1 was repeated, but with the exception that in a continuously operating Ten-stage extractor was worked. The experimental conditions and results are as follows Table II summarized.

Table II for a viscosity index level

The results show that NMP under the same extraction conditions compared to furfural supplies a raffinate oil with a significantly higher viscosity index.

Test conditions
solvent Furfural NMP Solvent dosing in Volume percentage 400 150 Working temperature in ° C ... 67 60 Raffinate yield in volume percent 73 5 78.5 Characteristic values of the deparafnated raffinate: SUS viscosity at 37.8 ° C 353 378 SUS viscosity at 99.0 ° C 54.3 55.7 Viscosity index 89.5 90.0 Pour point in ⁰ C -12.2 -9.4 Lovibond color number (measured with a 1.27 cm cell) 45 40

For a viscosity index level

Test conditions solvent

660 85

59.7

202 60

72 _; 7th

Solvent dosage in percent by volume

Working temperature in ⁰ C ...

R.affinate yield in percent by volume

Characteristic values of the
dewaxing raffinate:

Specific weight in

° ^API

SUS viscosity at 37.8 ° C SUS viscosity at 99.0 ⁰ C

Viscosity index

^ Setting point in ⁰ C

This long-term operation test also shows the strong superiority of NM P over furfural; a given viscosity index of the raffinate oil could be with NMP in much lower dosage and with A lower working temperature and on top of that with a higher raffinate oil yield.

NMP

29.5 29.4 306 252 53.0 49.8 100.0 100.0 12.2 -15.0

Example 3

A vacuum distillate fraction (lubricating oil feedstock) designated as 300 pale stock Naphthenic crude oil was treated with NMP under the conditions set out in Table III. the Characteristic values of the starting material, raffinate oil and extract are summarized in Table IV.

Table III Test Conditions

Solvent dosing in Volume percentage

Extract outlet temperature in ⁰ C. Raffinate outlet temperature in ⁰ C. Raffinate yield in percent by volume

150 60 77 81.6

Table IV Characteristic values of raw material, raffinate oil and extract

Specific weight in ⁰ API COC flash point in ⁰ C SUS viscosity at 37.8 ⁰ C SUS viscosity at 99.0 "C Pour point in ⁰ C Ash in percent by weight C residue in percent by weight Neutralization number Aniline point in ⁰ C Basic N ₂ , ppm Sulfur in percent by weight Lovibond color value

at the beginning (measured with a 15 cm cell) ....

after 24 hours (measured with a 15 cm cell)

at 99 ° C

after 24 hours (measured with a 1.27 cm cell)

at 99 ° C

Lovibond color fastness

(measured with a 1.27 cm cuvette) at 204 ^° C

initially

after 1 hour

after 2 hours

Refractive index at 70 ⁰ C SOD lead corrosion test at 163 ° C, weight change

mg / cm ² after 1 hour

mg / cm ² after 6 hours

Toettcher paint test, 13 hours at 177 ° C

Varnish, mg

Viscosity increase at 99 ° C in% Neutralization number Wännetest, 125 hours at 204 ⁰ C. Evaporation loss in% Increase in viscosity cSt at 99 ° C in% Neutralization number

mud

Source material

20.6 204 436

50.2 -28.9 0.001 0.03 0.02 76 179 0.21

345

95

80 15th 165 45 260 90 1.4954 1.4805 -1.02 -0.62 -7.53 -2.91 184 21.0 100 HO 6.8 9.4 4.0 73.5 46.4 0.95 1.5 none none

Raffinate oil

23.8 191 338 48.2 -31.6 0.001 0.04 0.02 87

0.13 95 160

extract

7.6 199

73.6 -3.9

0.58

1.5617

The SOD lead corrosion test is based on regulation MIL-L-708 C for lubricating oil, aircraft turbine oil synthetic base dated November 2, 1955 and in U.S. Patent 3003963.

The Toettcher paint test is described in U.S. Patent 2,674,577.

The Wännetest is an industry-like test to determine the thennischen Stability. Here, 250 ml of the oil sample Heated to 12PC for hours and then left to stand at room temperature for a day. Here is used to determine evaporation loss weighted. Furthermore, the viscosity is determined and with the viscosity of the oil before heating resembled. Finally, the number of neutralizations and the presence or absence of sleep are also included definitely

This example shows that NMP Extraki recovered raffinate oil compared to the output

material significantly more favorable parameters in terms of color and color stability. Corrosiveness and heat resistance wedge having.

Example 4

The wax distillate 20 oil starting material used in Example I wui.Jc with NMP im

Quantity ratio of NMP to lubricating oil starting material of 1.5: 1 at an outlet temperature of 69 ⁼ C for the extract and 99 ° C for the raffinate (yield: 68.6 percent by volume). The characteristics of the lubricating oil starting material, raffinate oil and extract are summarized in Table V below.

Table V

Specific weight in API

COC flash point in C.

SUS viscosity at 37.8 C

SUS viscosity at 66.0 C

SUS viscosity at 99.0 C

Viscosity index

Pour point in ⁰ C

I .ovibond color value

at the beginning (measured with a 1.27 cm cell) ..

at the beginning (measured with a 15 cm cell) after 24 hours at 104 ° C

(measured with a 1.27 cm cell)

after 24 hours at 104 ^° C

(measured with an i5 cm cell)

C residue in percent by weight

Ash in percent by weight

Neutralization number

Sulfur in percent by weight

Basic N ₂ , ppm

Refractive index at 70 ⁰ C

Lubricating oil output material

25.3
232
437

57.0
78.5
38

150
280

Raffinate

30.0 246

280

51.6 100.5 41

15th

- 35 0.10 0.006 0.001 0.001 0.40 0.03 0.22 0.07 34 - 1.4805 1,463

extract

15.4 243

424 100.4

32

0.58

1.5189

Lubricating oil feedstock and raffinate oil were then treated with paraffin and examined for a pour point of -15 ⁰ C ent re on their characteristics; these are compiled in the following table VI

Table VI

Depa refined lubricating oil base painting

NMP-refined, egg-paraffinized "lubricating oil

Specific weight in ⁰ API

COC flash point in ⁰ C

SUS viscosity at 37.8 ° C

SUS viscosity at 99.0 ⁰ C

Viscosity index

Pour point in ⁰ C

Ash in percent by weight

C residue in percent by weight

Neutralization number

Sulfur in percent by weight

Lovibond color value
(measured with a 1.27 cm cell)

initially

after 24 hours at 104 "C

24.0 238 608 61.8 62 -15 none 0.10 0.55 0.23

380 480

29.6 238 346

54.4

93 -15 none

20 30

209639 / Z

continuation

10

Lovibond color stability at 204 C (measured with a 1.27 cm cell)

initially

after 1 hour

after 2 hours

SOD lead corrosion test at 163 C) Weight change

mg / cm ² after 1 hour

mg / cm ² after 2 hours

Spindcl oil oxidation test, 24 hours at 121 ¹ C ² )

Soaping number

Neutralization number

Viscosity increase at 37.8 ° C in% heat test. 125 hours at 204 C ^J )

Evaporation loss in%

Viscosity increase

cSt at 99 C in%

Neutralization number
mud

t: ntpiraffinicrlcs

Lube initial painting

8.06
67.43

2.8
0.74
12.6

0.8

35.9

23.6

1.6

none

NMI'-ra ffinierlcs. cmparaffinicrlcs lubricating oil

20th
45

6.26
38.44

3.1
0.38
11.3

1.3

21.0
11.2
1.2
none

SOD corrosion test and heat test were carried out according to the instructions given in Table IV.

² I When Spindclöl-Oiydationstcst is heated, the oil to be tested in the presence of steel, copper and Blcistrcifcn for 24 hours while blowing air onto I2PC and thereafter examined for viscosity increase and saponification and Ncutralisationswertc.

³ ) As with Table IV

As the results of this example show, NMP refined oils are not compared to those Refined lubricating oil starting materials are lighter in color and show improved characteristics for color and corrosiveness and heat resistance.

Example 5

In this example, NMP was rated for its effectiveness in lube oil refining using solvent extraction compared with the unsubstituted 2-pyrrolidone. To this end, on the one hand a low-viscosity and, on the other hand, a medium-viscosity lubricating oil starting material among the same Extraction conditions with NMP or 2-pyrrolidor

brought into contact. It turned out that the Ver The use of NMP led to a far greater increase in the viscosity index. It could not same temperature and dosage conditions to extract three times more material than 2-pyrrolidone

NMP produced a raffinate oil with a far lower refractive index, the lowering being the case of medium viscosity Lubricating oil feed was stronger than the low viscosity lubricating oil feed.

1 sheet of drawings

Claims (1)

also already used to improve the color of oil, d. H. to the patent claims: Removal of less than 1% of coloring constituents from a lubricating oil starting material, 1. Method for obtaining a lubricating oil, used. characterized in that one em 5 was previously unknown, however, that N <viF in addition to Lubricating oil starting material with N-methyl-2-pyr- its ability to selectively remove thermal brings rolidon into contact in such a dosage, mixed and oxidative inadequately stable constituents that at least part of the lubricating oil starting material (aromatics, olefins) from paraffinic carbon 10 percent by volume of material can be dissolved. Hydrogen mixtures other substances with low 2. The method according to claim 1, characterized in that io drigem viscosity index, in particular naphthenic draws that the N-methyl-2-pyrrolidone and polynaphthenic substances with relatively short Dosage, based on the lubricating oil output side chains effective from lubricating oil output material, holds between about 50 and 450%. able to remove supplies. 3. The method according to claim 1 or 2, thus the subject matter of the invention is a method characterized in that the contact temperature 15 to obtain a lubricating oil, which thereby temperature between 10 and 121 "C. is characterized that a lubricating oil outlet 4. The method according to any one of the preceding material with N-methyl-2-pyrrolidone in such Do claims, characterized in that one brings into contact with that of lubricating oil Crude oil vacuum distillate as lubricating oil input material at least 10 percent by volume material material runs out. 20 to be resolved. When performing the Lubricating oil starting material used according to the invention has been through successive Distillation, preferably in vacuo, obtained. The lubricating oil treated according to the invention is 25 then dewaxed, treated with an inhibitor In the production of lubricating oils from crude oil sets and blends. The finished lubricating oils need If one or more of the lubricating oils are distilled, in contrast to known methods Fraction (s) containing constituents, usually extracted lubricating oils, no final treatments, in a vacuum. This raw or weak hydrogenation or clay or acid lubricating oil fraction (s) naturally contain pretreatment. The NMP dosage is within the range coming, unstable substances due to the heat of the method according to the invention, based on action and / or oxidation to form the lubricating oil starting material, preferably between Precipitation in the facilities and / or to see about 50 and 450%. The temperature at which They tend to corrode. In the case of paraffinic oils, the lubricating oil starting material in contact with NMP must also be brought to the viscosity often, preferably between 10 and Activity index can be increased by removing it from the 12PC. contained therein and for a lowering of the When carrying out the method according to the Viscosity index responsible polyaromatic, invention one obtains a lubricating oil refinate from ver Naphthenic and polynaphthenic substances have a better viscosity index and a higher thermal one especially freed with short side chains. To 40 and oxidative stability. With lubricating oil on the base for this purpose one must have a considerable amount of the paraffinic petroleum one needs to achieve Substant of commercial goods contained in the lubricating oil starting material only has to deparaf the raffinate zen, namely depending on the desired end product finish and to be treated with an inhibitor, while at properties z. B. about 10 to 60%, remove or even naphthenic lubricating oils only the inhibitor destroy. For this purpose it is known that an example rate is required. wise from the German patents 629 762 and The solvent extraction by means of NMP 1 180 725, the lubricating oil starting material with a sirh for the production of lubricating oils based on petroleum, solvent, e.g. furfural, which compared to the more unstable molecules of mainly aromatic lubricants like them for the production of crankcase unstable molecules , as well as of naphthenic oils, such as a non-hydrocarbon-like character, they z. B. for the production of turbine lubricating oils is selectively effective to extract. Although those are used. The viscosity index is extraction ability of furfural for aromatics and oil starting material ai ^'r between petroleum-based non-hydrocarbons as satisfactorily proved to about 40 and 105; when refined according to the invention, its selectivity allows polynaphthenic lubricating oil to be at least 10 units higher. There is still a lot to be desired when it comes to ties. This loading 55 paraffinic petroleum oil feedstocks ardeutet that an extracted with furfural lubricating oil to beitet at temperatures of about 49 to 12PC, still not the desired preferably starting material of from about 60-82 ⁰ C, and a Menhohen viscosity index. gene ratio of NMP to lubricating oil starting material It is also known, for example from German, from 0.5 to 4.5: 1, preferably 1 to 3.4: 1. In patent specification 1 180 725 see that N-methyl-naphthenic lubricating oil starting materials ar-2-pyrrolidone (abbreviated NMP) as a solvent is worked at temperatures of 10 to 93 ⁰ C, before the selective separation of pure aromatics from preferably 24 to 66 ⁰ C, and with a quantity of aromatic hydrocarbon mixtures and ratio of NMP to lubricating oil starting material of 0.5 as a selective solvent for the separation of up to 3.0:!, Preferably from 0.75 to 2.0: 1. Note olefins and aromatic hydrocarbons of 65 worthwhile, the solvent dosage for paraffinic hydrocarbons is suitable (cf. use of NMP around 50% below that of the specification of the General Aniline & Film Corporation "methyl pyrrolidone", usually used as a selective solvent, 1961). Eventually, NMP became furfurols.